The LOI as it is now used is a misunderstood application of poorly informed brokers and traders. A more proper application based on established custom and practice in International trade, going back even to the old medieval "Law Merchant" (Lex Mercantilis) is: Buyer requests a quotation _ in modern usage this is an RFQ/Request For Quotation _ NOT an LOI. Seller may then reply with a Quote. Buyer confirms receipt of quoted prices, and requests an Offer.
"My advice [to parties contemplating having an LOI] is to proceed with caution before signing any such document. As a general rule (and there are exceptions), I urge the parties to go right to the final documents and "dot all of the I's and cross all of the T's," rather than go through this interim step of a letter of intent, which has many potential traps."